There are many systems for treating and removing thrombi from a patient. Traditional methods involve the administration of blood thinning medicaments (thrombolytic agents) which are intended to dissolve thrombus material, which can then be dispersed in the blood stream. Other systems use filters for capturing thrombus material, which can then either be removed along with the filter or dissolved with appropriate medicaments. Yet other systems involve aspiration of thrombus material through a retrieval catheter.
Existing methods are generally successful in removing many types of thrombi but are not normally able to remove thrombi formed of denser material, such as found in older thrombus formations. Such thrombus material does not generally dissolve readily with thrombolytic drugs at physiologically safe concentrations and cannot readily be aspirated into a catheter. Moreover, such thrombi tend to be attached to the vessel wall, with the result that filtration is an ineffective tool for removing them.
A thrombus formation should not be left untreated in the patient given the risks caused by its fragmentation and the fact that the thrombus will generally continue to grow, eventually occluding the vessel in which it is located.
Examples of thrombus capture and removal devices and solenoid operated medical tools can be found in US-2010/0,318,117, US-2010/0,023,033, US-2010/0,022,943, U.S. Pat. No. 5,520,635, WO-02/100,460 and US-2007/0,156,164.